Electrode conduction processes in air plasmas

1962 ◽  
Vol 13 (3) ◽  
pp. 465-477 ◽  
Author(s):  
D. W. George ◽  
H. K. Messerle
Keyword(s):  
Magnetic Field ◽  
Shock Tube ◽  
Current Flow ◽  
Electronic Conductivity ◽  
The Other ◽  
High Current ◽  
Air Plasma ◽  
Air Plasmas ◽  
Current Densities

Using an electrically driven shock tube with initial pressures of 0.1 to 1.0 mm Hg and shock speeds of about Mach 12 to 15, the resistance of an air plasma between two parallel probes has been measured by two different techniques and the results compared. In one, external voltages of from 0 to 100 V were applied to the probes and in the other, electromagnetically induced voltages of from 0 to 25 V were produced by the plasma's motion in a magnetic field of up to 3500 G. In either case the resistance was found to decrease as the current flow increased and was consistent with the equilibrium electronic conductivity of the air plasma at high current densities.

scholarly journals A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiaxin Yuan ◽  
Xiaodi Cheng ◽  
Hanqing Wang ◽  
Chaojun Lei ◽  
Sameer Pardiwala ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Active Sites ◽  
Electronic Conductivity ◽  
Three Dimensional ◽  
Active Surface ◽  
Alkaline Media ◽  
Active Surface Area ◽  
High Current ◽  
High Electronic Conductivity ◽  
Current Densities

AbstractCost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction (OER) are critical to the energy crisis and environmental pollution. Herein, we report a superaerophobic three dimensional (3D) heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy (NiSe2/NiFe2Se4@NiFe) prepared by a thermal selenization procedure. In this unique 3D heterostructure, numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~ 100 nm are grown on NiFe alloy in a uniform manner. Profiting by the large active surface area and high electronic conductivity, the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media, outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm−2, respectively, which is among the most active Ni/Fe-based selenides, and even superior to the benchmark Ir/C catalyst. The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.

scholarly journals New Measurements of the Transition to the Normal State Induced by High Current Densities in High-Tc Superconductor Microbridges under Thermal Smallness Conditions

2014 ◽  
Vol 95 ◽  
pp. 202-206 ◽  
Author(s):  
J.M. Doval ◽  
J. Maza ◽  
C. Torron ◽  
J.A. Veira ◽  
M. Tello ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Diffusion Length ◽  
High Current ◽  
Flux Flow ◽  
High Tc ◽  
High Tc Superconductor ◽  
Dimensional Scaling ◽  
Current Densities ◽  
Millisecond Range

We address here the superconductivity quenching under an external magnetic field of amplitudes up to 1 T and in the so-called "thermal smallness" condition, when the microbridge width becomes smaller than the thermal diffusion length of both the own superconductor and its refrigerant (the substrate, in the case of thin films), which breaks their thermal dimensional scaling. Our results further support that when the current perturbations have characteristic times in the millisecond range the quenching is due to thermal instabilities associated with regular (nonsingular) flux-flow, and they also suggest how to optimize the refrigeration of practical superconductors.

scholarly journals ELECTROOSMOSIS IN NITELLA

1957 ◽  
Vol 41 (2) ◽  
pp. 383-396 ◽  
Author(s):  
L. R. Blinks ◽  
R. L. Airth
Keyword(s):  
Current Flow ◽  
Water Movement ◽  
High Current ◽  
Negative Pole ◽  
Low Salt ◽  
Current Densities ◽  
External Connection ◽  
Very High ◽  
Bioelectric Potentials

The role of electroosmosis was studied directly in Nitella. The cells were mounted in a water-tight barrier between two chambers containing reversible electrodes for the application of potentials, and fitted with calibrated capillaries to measure water movement. No water movement was found when small existing bioelectric potentials were short-circuited through an external connection, nor when external potentials up to 1 or 2 volts were applied (producing currents up to 5 µa). Higher potentials (up to 10 volts) caused small movements of water, toward the negative pole. Larger and often irreversible water movements were produced by potentials up to 20 volts—sometimes persisting after current flow. A variety of evidence suggests that the effects are caused by injury at the cathodal end of the cell, allowing water to be attracted osmotically at the intact end and forced out at the injured end (transosmosis). This injury is reversible under small applied potentials, irreversible after large ones (100 to 200 times the natural bioelectric values). Such water flows persist in low salt concentrations (up to 0.09 M NaCl) but almost completely vanish in isotonic (0.26 M) mannitol. This confirms the osmotic, rather than the electroosmotic nature of the water movement. It is estimated that electroosmosis cannot account for more than 1 per cent of the water movement (or turgor) in Nitella cells. The dead cellulose walls display a small electroosmotic water flow at very high current densities (under 20 volts applied potential).

Study of MFM Application in Semiconductor Failure Analysis

2004 ◽  
Author(s):  
Way-Jam Chen ◽  
Lily Shiau ◽  
Ming-Ching Huang ◽  
Chia-Hsing Chao
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Current Flow ◽  
Force Microscopy ◽  
The Magnetic Field ◽  
A Current

Abstract In this study we have investigated the magnetic field associated with a current flowing in a circuit using Magnetic Force Microscopy (MFM). The technique is able to identify the magnetic field associated with a current flow and has potential for failure analysis.

scholarly journals B‐Cu‐Zn gas diffusion electrodes for CO2 electroreduction to C2+ products at high current densities

2021 ◽  
Author(s):  
Yanfang Song ◽  
Joao R. C. Junqueira ◽  
Nivedita Sikdar ◽  
Denis Öhl ◽  
Stefan Dieckhöfer ◽  
...  
Keyword(s):  
Gas Diffusion ◽  
High Current ◽  
Gas Diffusion Electrodes ◽  
Co2 Electroreduction ◽  
Current Densities

scholarly journals Ground state and stability of the fractional plateau phase in metallic Shastry–Sutherland system TmB4

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matúš Orendáč ◽  
Slavomír Gabáni ◽  
Pavol Farkašovský ◽  
Emil Gažo ◽  
Jozef Kačmarčík ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Diagram ◽  
Ground State ◽  
Constant Magnetic Field ◽  
Paramagnetic Phase ◽  
The Other ◽  
Zero Field ◽  
Plateau Phase ◽  
Low Field ◽  
Zero Field Cooling

AbstractWe present a study of the ground state and stability of the fractional plateau phase (FPP) with M/Msat = 1/8 in the metallic Shastry–Sutherland system TmB4. Magnetization (M) measurements show that the FPP states are thermodynamically stable when the sample is cooled in constant magnetic field from the paramagnetic phase to the ordered one at 2 K. On the other hand, after zero-field cooling and subsequent magnetization these states appear to be of dynamic origin. In this case the FPP states are closely associated with the half plateau phase (HPP, M/Msat = ½), mediate the HPP to the low-field antiferromagnetic (AF) phase and depend on the thermodynamic history. Thus, in the same place of the phase diagram both, the stable and the metastable (dynamic) fractional plateau (FP) states, can be observed, depending on the way they are reached. In case of metastable FP states thermodynamic paths are identified that lead to very flat fractional plateaus in the FPP. Moreover, with a further decrease of magnetic field also the low-field AF phase becomes influenced and exhibits a plateau of the order of 1/1000 Msat.

scholarly journals B‐Cu‐Zn gas diffusion electrodes for CO2 electroreduction to C2+ products at high current densities

2021 ◽  
Author(s):  
Yanfang Song ◽  
Joao R. C. Junqueira ◽  
Nivedita Sikdar ◽  
Denis Öhl ◽  
Stefan Dieckhöfer ◽  
...  
Keyword(s):  
Gas Diffusion ◽  
High Current ◽  
Gas Diffusion Electrodes ◽  
Co2 Electroreduction ◽  
Current Densities
Sign in / Sign up

Export Citation Format

Share Document